<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            color:yellow;
        }
    </style>

    <script src="./react/react.development.js"></script>
    <script src="./react/react-dom.development.js"></script>
    <script src="./react/babel.min.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel">

    //JSX=JS+xml、


    let app = document.querySelector('#app');
    let root = ReactDOM.createRoot(app);

    //挂载节点,浏览器不认识，需要用babel转换
    let element = <h2 title='hi'>hello world</h2>;

    //挂载子节点
    // 标签要小写
    // 单标签要闭合
    // class属性与for属性
    // tabindex × tabIndex 单属性驼峰
    // 自定义属性随意
    // 唯一根节点：加div
    element = (
        <div>
            <h2 title='hi' className="box">hello world
                <span>!!!!</span>
                <label htmlFor="elemInput">用户名
                    <input type="text" tabIndex/>
                    <input type="text" tabIndex/>
                </label>
            </h2>
            <p>123</p>
        </div>
    );

    root.render(element); 

</script>
</body>
</html>